Re: Pluggable Indexes

Gregory Stark wrote:
> Simon Riggs <simon@2ndQuadrant.com> writes:
> 
>> The original design of Postgres allowed pluggable index access methods,
>> but that capability has not been brought forward to allow for WAL. This
>> patch would bridge that gap.
> 
> Well I think what people do is what GIST did early on -- they just don't
> support recoverability until they get merged into core.

What other constraints are there on such non-in-core indexex?  Early (2005)
GIST indexes were very painful in production environments because vacuuming
them held locks for a *long* time (IIRC, an hour or so on my database) on
the indexes locking out queries.  Was that just a shortcoming of the
implementation, or was it a side-effect of them not supporting recoverability.
If the latter, I think that's a good reason to try to avoid developing new
index types the same way the GIST guys did.